[ QUOTE ]
I've read that at the lowest limit STT's, a 30% ROI would be reasonable for a good player, and that a STT might take an hour.

[/ QUOTE ]Two things: at the lowest limit SNGs you can probably do better than 30% ROI and they only take an hour if you win (or show) -- when you are out of the money they won't take as long, so you might figure 20-30 minutes for an average SNG.